There are a number of issues that must be considered to address the intelligibility of the incarnation. First, the groundwork of metaphysics must be laid. What are a nature and a person? Is it possible for one person to have more than one nature? How can three persons of the Trinity be individuated in one substance? Second, we must turn to concerns regarding the compatibility of two natures in one person. Can the divine and the human co-exist in one individual? The problems of knowledge, will, and temptation must be answered plausibly. We will consider these issues and conclude that the incarnation is metaphysically possible and belief in it is rational. I will present a model for these answers consistent with Christian orthodoxy.
I have long been impressed at the philosophic and theological sophistication of the early church councils as they addressed the challenges raised to and in the church. The ecumenical councils draw the parameters around orthodox faith, and any solutions postulated must be found within these limits. There are also philosophic categories that seem somewhat clear and must be respected when attempting to synthesize the information from the Bible about the incarnation. These are my concerns as I attempt to describe a rational account for the incarnation, and I find that it is possible to answer the questions within these constraints. The solution to the incarnation must affirm that Jesus is one person with divine and human natures, and the second person of the Trinity.
A person is a category of immaterial conscious substance. There seem to be three types of persons that we know of: God, angels, and humans. Persons are essentially souls. There are some capacities that are common to all persons: cognition, rationality, affect, volition, desire, perception, and morality are examples. The substance person cannot be analyzed in functional terms or the properties it possesses; rather it is constituted by a set of ultimate capacities and the universals it exemplifies, regardless whether or not they are ever realized. The mere possession of the capacities and universals counts for personhood.
Jesus is a person in virtue of being God, therefore He is of the same type of conscious being as humans. It would not be appropriate or possible for Jesus to become a non-person, for instance an animal or a non-conscious thing.
Substances possess properties and remain identical to themselves through time and change. Joshua Hoffman and Gary S. Rosenkrantz define substance in their book Substance: Its Nature and Existence:
X is a substance = df. X is an instance of a concrete category, such that: it could have a single instance throughout an interval of time (non-minimal).1
A substance can be instantiated as an individual, concrete particular, a member of a general kind, that is traceable through a duration of time.2 The instantiation of a substance possesses the properties predicated of it. A substance is a natural kind that is marked off by “a set of its ultimate capacities that are possessed by it solely in virtue of the substance belonging to its natural kind.”3 Membership in the natural kind is constant through a person’s existence, it tells us what a thing is, and the individuation of the kind is the ground of identity through change.
A substance cannot loose its essence and continue to exist. This is necessarily true if Jesus is to remain identical to the second person of the Trinity through the incarnation. The Council of Nicaea affirmed that Jesus was of one substance with the Father and the Spirit; He shared in the identical personal natural kind and continued to throughout the incarnation.
Persons qua persons are immaterial substances, but it is a unique property of human persons that they possess material bodies, thus it must be a property of the nature and not personhood. A nature is a set of essential properties that further mark off what sort of thing an individual is. There are three kinds of persons that we know of: God, angels, and humans. The further distinction between these kinds of persons is the natures they possess.
Orthodoxy holds that all of God’s properties are essential, but angels and humans have essential properties in virtue of their natures and accidental properties in virtue of their individual existence. Among God’s necessary properties are perfection, omniscience, omnipotence, and omnipresence. Jesus could not lose these and continue to be identical to the second person of the Trinity.
In determining what are the essential properties of human nature, we must take into consideration the distinction between what is universal to all humans versus what is essential to all humans. Thomas Morris points out that it is universal that all human persons live on the surface of the earth, but that does not mean that it is essential that they do.4 Humans could live in a space lab for their entire bodily duration and still be human. It is also the case that all humans sin, but that is a universal property not an essential one since it is possible for humans to live without sin. Morris points out a further distinction that follows from this, “In order to be fully human, it is not necessary to be merely human. An individual is merely human just in case it has all the properties requisite for being fully human...and also some limitation properties as well.”5 This distinction will be helpful in solving issues of apparent incompatibilities between divine and human natures. Jesus is fully human, all that humanity was meant to be; the rest of the members of the human race are merely human, limited by the influence of sin.
The best test I can think of for determining what is essential to human nature is to ask the question: Is it possible for human beings to exist without a particular property? When this test is administered to many properties that appear to be essential to humanity, it becomes clearer that most properties are probably contingent on the kind of bodily, earthly existence we experience now. For instance, I began thinking that sexual interest and emotional needs for relationship were essential; however, it seems very likely from the Biblical witness that humans will not function sexually in the after life, nor have the kinds of emotional needs for others that we have now. It could be that these contingent needs are precursors to more ultimate satisfactions that we will experience in Heaven. Many nature property candidates fall by the wayside in the conceivability test.
The properties that seem to be essential to human nature are those that the professor presented in class, with one exception in my opinion. A substance S has the essence or nature of humanity iff(df):6
- S is a person (a soul).
- S is or has been embodied as a living organism of the natural kind homo sapiens (with a micro-structural blueprint, which marks it as a natural kind) such that:
- normally, S apprehends objective reality (universals and particulars; tokens and types) perceptually
- S’s development (the realization of S’s higher-order capacities) is (at least partly) tied to the development of S’s body
The one point of disagreement in the form of the definition given in class is the spirit capacity for relationship with God. I think this is a better candidate for a capacity of persons because the two examples of persons we know of besides God do have relationship with Him (and actually He has relationship with the other persons of the Trinity). And if it is a capacity of persons to behave morally, and morality seems to be necessarily grounded in God’s existence, then it appears that all persons would have the capacity for relationship with God to ground their morality and the obligation feature that follows.
It has been suggested that the definition of human nature would be improved with the qualification that embodiment is only possible. I think that it is an essential property of human nature to be or have been embodied, not possibly embodied. If the incarnation was necessary in any way (and there appear to be several good reasons why it was) then bodily existence is necessary for humans, otherwise Jesus could have taken on human nature and remained immaterially existent. Since it seems that His physical incarnation was likely necessary, then it seems reasonable to conclude that physical embodiment is not accidental to human nature.
With this metaphysical framework set, we can propose an analysis of what a human being is. A human is:
- a personal substance
- that possesses the set of essential properties of human nature, and
- is embodied in its usual state of existence.
Jesus was fully human by this analysis.
God is also a substance, but instead of the usual one-to-one correspondence of persons and substance that we are familiar with, God is three persons in one substance. The divine nature, shared by all three persons of the Trinity, is able to be instantiated only once. God is a union of three persons.7 The witness of the Bible is that God is one (Deut. 4:35). It also seems necessarily true that there can only be one being with the divine essence if God’s maximal attributes are understood in a comparative sense.8 God’s attributes cannot be exceeded or rivaled by any being.
Though unique, there appears to be no incoherence to the concept. This substance has the essential properties of divine nature. Each person of the Trinity is a center of consciousness with His own personal capacities.
Jesus was a preexistent personal soul with a divine nature that added a human nature, and thus a body, to His substance. Again, though it is a unique case for a person to have two natures, it seems possible for two personal natures to be coexemplified as long as their essential properties are not mutually exclusive. Because the second person of the Trinity had the same personal substance as the incarnated Jesus, they are identical persons. Though this person added a new nature, His essential properties did not change. Because natures are essential properties which cannot be lost without going out of existence, Jesus continues to have two natures. The incarnation was not a temporary event.
There are some particular objections to the coexemplification of certain properties of divinity and humanity that must be considered. Appealing to Morris’ distinction between universal and essential properties, and between fully human and merely human can answer these sorts of objections, such as contingency and omniscience. Contingency is universal in most cases of humans in virtue of being created beings, but it does not seem to exclude the idea of an infinite being taking on a human nature.
Omniscience is another particular case that seems to be incompatible with limited human nature. Limited knowledge also does not have to be essential to humans. Limited knowledge may be a result of being contingent beings, not human qua human. It also may be a limitation of embodiment in unglorified form. It certainly seems likely that in Heaven with glorified bodies and an eternal amount of time to learn, that our set of knowledge will increase beyond what is imaginable now.9
But what of the reverse: Can God limit His knowledge? Jesus seemed to exemplify genuine limits on His knowledge at times. There are examples in the Gospels where Jesus’ intent seemed to be to learn propositional knowledge. This seems to be the natural implication in Luke’s statement that “Jesus kept increasing in wisdom and stature, and in favor with God and men” (Luke 2:52). There are other cases where Jesus seems to truly acquire propositional knowledge (John 11:34; 18:34).
How could the omniscient divine mind be contained by a limited human mind when joined in the one person of Jesus? Aquinas’ solution was that Jesus the man fully realized all of the latent capacity for knowledge that is natural for a human to have, but He was not omniscient.10 Proximity to the divine essence inspired the full realization of the human capacities. In addition, Jesus exemplified the state of body and soul common in the after life when the greater capabilities of the soul will not be limited by the present conditions of physical union to the body. Jesus’ soul dominated His physical restrictions to realize it’s fullest potential. Though this solution gets Jesus a larger stock of knowledge than the usual human being, even an optimally functioning human mind is only finite and not omniscient.
One solution would be to suggest that Jesus had two minds, but the mind seems to be the rational capacity of the soul. Two minds would mean Jesus had two souls and two identities, and that is metaphysically unacceptable based on the account laid out earlier. Morris characterizes the relation between the two minds of Jesus as asymmetrical: As God, He was aware of the human mind, but as a man, He was not aware of the divine mind and functioned as if it were the only one He possessed.11 Morris proposes that Jesus had two centers of consciousness. He believes that while Jesus was one person, there were two hypostases. Though Morris does recognize the burden of solving the apparent problem of synchronic identity, I do not believe his metaphysical characterization can accomplish that. Richard Mull defines hypostases as a self-subsisting person, not simply a center of consciousness.12 This is the language the ecumenical councils used to affirm the unity of Jesus’ person (hypostases) with two natures. It does not appear that a satisfying metaphysical account can be given for the two minds view that also affirms one personal identity.
Richard Swinburne seems to endorse a similar view in The Christian God and cites Thomas Morris, as well. Swinburne characterizes his version of the two minds view as two separate belief tracks, the human belief track being unaware of the divine belief track.13 The belief tracks operate in the nature, so that Jesus had a divine way of thinking and acting and a human way of thinking and acting. Each nature also has a separate will. However, I do not believe Swinburne gives enough justification to override the previous metaphysical account of the personal substance possessing the rational and volitional capacities constituting one rational individual.
The other possibility is that Jesus had one mind and one intellect and did not make use of His omniscience. This would be consistent with the kenosis by addition advocated by Millard J. Erickson.14 When Jesus added human nature to His personal substance in the kenosis, He willingly chose not to make use of His divine attributes during His duration on earth. He retained His divine essence, but added human nature and chose to live with human limitations. But as Erickson points out, the divine also limited the human nature in that it prevented Jesus’ human nature from be merely human. The influence of the divine nature helped Jesus to live fully as a human without any of the limitations of sin and contingent creation.
On this view, then, Jesus willed to limit the knowledge He made use of as a man to a subset of His divine knowledge. But as fully human and not merely human, Jesus’ realized the ultimate cognitive capacity natural to humans. In this way, the second person of the Trinity remained omniscient, but also lived as a limited human during His mission.15
A question that has challenged the orthodox view of the incarnation since the early first millennium is the nature of Jesus’ will. How many wills did Jesus have? Constantinople III concluded that Jesus had two wills and rejected monothelytism. This is the only issue of the first six ecumenical councils that I am aware of that I take issue with their conclusion because I believe it was based on an ill-conceived metaphysic. Constantinople was wrong in locating the will in the nature. The will is an active power that is a capacity of soulish creatures. More specifically, persons have rational wills; this is true of different beings that belong to the category of persons, including humans, angels, and God. So the will seems to be a soulish capacity, and the rational will is a capacity of persons. All persons also have natures, but their natures are unique to each kind, so it seems reasonable to place the will in what is common to all who have one. If a person is a soul, then Jesus had only one will. He had one will as the preexistent second person of the Trinity and did not add another when He added a human will.
How do we reconcile Jesus’ words, “Father, if Thou art willing, remove this cup from Me; yet not My will, but Thine be done” (Luke 22:42)? This verse was a primary motivating factor in the Council’s conclusion. It appears that Jesus’ human will was in conflict with the divine will. A few of things should be said regarding this.
First, Jesus’ human will was never in opposition to the divine purpose because, due to His impeccability, Jesus’ human will was in perfect subordination and coordination with the divine will. This is another example of the divine influencing the human nature to be fully human.
Second, Jesus may not have been using “will” in a technical sense, but rather was referring to a desire. It could be that since different kinds of persons have different kinds of desires that desires are influenced by dispositions in the nature. The nature is what gives the personal faculties their unique essence, so different kinds of persons would have different kinds of desires because of their different natures. As an embodied human being, Jesus had a disposition to be fearful of the suffering and death that lay ahead of Him. Swinburne points out that it is not necessary to act on a desire, especially when there is also a countervailing stronger desire. Jesus’ desires influenced by His divine nature would always be stronger than those influenced by His human nature. Swinburne says, “A divine individual could not have what we normal humans so often have—a strong desire, not outweighed by a contrary desire, to do an action less good than the best available.”16 What Jesus expressed in His prayer was a real human desire to avoid the cross, yet His will to carry out His mission remained constant and unmoved by the influence of His divine nature.
Third, this prayer to the Father is consistent with the conclusion that each person of the Trinity has their own will. The second person of the Trinity submitted His will to the Father’s. This does not imply disagreement; the wills of the Trinity are perfectly consonant and are always concurrent with one another because they share the same nature and same desires.
On this account, Jesus was saying, “Not my desire, but Yours be done.” His human desire was different than the Father’s, but because of His single will, which is perfectly coordinated with the Father’s and the Spirit’s, He did not act on that desire. Instead He acted on the overriding desire of His divine nature to carry out the work of salvation.
Another challenge of the incompatibility of the coexemplification of the divine and human is temptation. The testimony of the Bible is that Jesus was tempted (Luke 4:2), but Scripture also tells us that God cannot be tempted (James 1:13). This must be reconciled if the incarnation is to be found rational.
It is possible that there is an equivocation on the term “temptation” in these passages. Reflecting on the background concepts of Jesus’ human nature and God’s nature is helpful. God is perfect without defect; it is impossible for sin to appeal to God. Therefore, God cannot be tempted. However, as a human, Jesus could be tempted in a different sense because of the weaknesses innate in human nature.
Sin never was attractive to Jesus since He was God, but as a human being He recognized possible means of fulfilling desires He possessed as a human being. The presentation of an unviable means could cause the experience of the unfulfilled desire to be more difficult. There is an innate weakness in the nature of being a contingent being that is aggravated by the presentation of illegitimate means of fulfillment. So even if Jesus knew that He would not sin, He still struggled with the weaknesses made more poignant by the options made available to Him. The temptation was directed to the vulnerability of these innate weaknesses and caused the struggle with unfulfilled desires. For example, the fear of the cross was real and natural for a human being, and there was the struggle with this fear to go through with it, though it was certain He would. After 40 days without food, Satan’s suggestion to turn the stones into bread was not a means attractive to Jesus, but it would still heighten the struggle to continue His fast. The temptation goes to the struggle with the legitimate desire, not the illegitimate means to fulfill it.
Temptation is essentially an internal attraction to an object so it would be possible to be tempted without sinning. The object may be a good object of desire or a wrong one. The circumstances of fulfilling that desire may be proper or they may not. Jesus could be tempted to a good object of desire in a context that would make it wrong if He were to follow through on His desire. For instance, He could have been attracted to a woman, but He didn’t act on that attraction because He was not married to her. And the desire qua desire isn’t necessarily lust. So that attraction, the essence of temptation, can be extracted from the other circumstances that would make it a sin. Jesus could be tempted (experience an attraction to a good object of desire) without sinning. It is usually the case with humans that other factors, internal and external, are concurrent with the desire that almost always makes sin simultaneous with temptation. In addition, normally the conditions to sin are present for human beings, but for Jesus there were no conditions under which He would sin because of His impeccability. His sinlessness was not de facto, but metaphysical. Yet the essence of temptation is the desire and He could experience that without the conditions or opportunity to sin or the concurrent factors that usually accompany temptation for humans. Further, Jesus knew He could not sin but, as a human being He felt the tug of His desires that He could not fulfill.
Another option is that Jesus did not know He could not sin, and He feared He might. Jesus may have voluntarily limited His access to His divine knowledge, including His knowledge of His divine identity. But the text seems to indicate that by the time of His ministry He was aware of His divinity and should have known that it was impossible for Him to sin.
Swinburne offers another option. He points out that Jesus willingly limited the exercise of His divine capacities in a way that made Him operate in a limited way and feel limited.17 Swinburne also points out the difference between sinning and not doing the greatest good.18 It is wrong to be attracted to sin, but it is not wrong to have a desire to do a good that is not the greatest good possible. As a man, Jesus was never tempted to sin, but He could be tempted to not perform the best action, especially when this exploited a natural human weakness.
This very well could characterize Jesus’ request in the Garden of Gethsemene. The only weakness I find in this option is that when Satan tempted Jesus in the wilderness, the options offered were in fact sinful, not just a lesser good. But this could be an explanation for other temptations Jesus experienced.
I must admit that this issue provides the least satisfactory answers for me. Temptation as the aggravation of unfulfilled desires does not seem to capture temptation as we experience it. Temptation qua temptation seems to be an attraction to the object. Swinburne’s characterization seems to best capture this feature. The intelligibility of the incarnation does not require a satisfying answer, only a rationally possible answer and that has been offered.
It has been demonstrated that particular objections to the coexemplification of the divine and human natures can be answered; and I believe the analysis offered provides grounds to believe that similar objections can be answered reasonably. It has been shown that it was possible for Jesus to willingly limit Himself to experience life as a human, and yet remain God with His essential attributes. It is possible to be a personal substance with two distinct natures. Jesus was fully man, not a mere man; He exemplified human nature operating at its fullest potential. Jesus was able to accomplish His mission and show us God’s great intent for humanity.
The concept of the incarnation bears up under philosophic scrutiny. The ancient creeds of Christendom and the articulation of one of the most fundamental Christian doctrines is found to be rational and commendable.